Cellular communications systems continue to grow in popularity and have become an integral part of both personal and business communications. Cellular telephones allow users to place and receive voice calls most anywhere they travel. Moreover, as cellular telephone technology has increased, so too has the functionality of cellular devices. For example, many cellular devices now incorporate personal digital assistant (PDA) features such as calendars, address books, task lists, etc. Moreover, such multi-function devices may also allow users to wirelessly send and receive electronic mail (email) messages and access the Internet via a cellular network and/or a wireless local area network (WLAN), for example.
Another feature which is being coupled with cellular communications capabilities is satellite positioning. That is, certain devices now incorporate both cellular and satellite positioning devices, such as global positioning system (GPS) devices, for example. One such device is described in U.S. Pat. No. 6,857,016 to Motoyama et al., which is directed to a computer remote position reporting device which includes a global positioning system (GPS) receiver, monitoring software and an Internet access module for tracking and mapping a position of a mobile object. In one embodiment, the obtained positions are collected, logged and communicated to a desired location by a store-and-forward protocol (e.g., Internet e-mail) or a direct-connection protocol (e.g., file transfer protocol (FTP)) via a wireless cellular transceiver.
As the functionality of cellular communications devices continues to increase, so too does the demand for smaller devices which are easier and more convenient for users to carry. As such, incorporating GPS capabilities in ever-smaller cellular phones becomes increasingly difficult, as smaller GPS antenna designs are required due to space constraints. Thus, one challenge for designers is to provide GPS antennas with adequate signal reception characteristics yet in a relatively small size.
Various attempts have been made improve mobile device satellite positioning antennas. An antenna arrangement for a GPS signal processing device is disclosed in U.S. Pat. No. 6,720,923 to Hayward et al. in which an antenna member is mounted on a circuit board. The antenna member includes first, second, and third surfaces. The third surface adjoins the first and second surfaces. The first, second and third surfaces define a cavity within which is disposed dielectric material. At least one conductive connector comprising first and second ends is in communication with the antenna member first surface, and an amplifier is in communication with each conductive connector second end.
Another example is set forth in PCT publication no. WO 02/29988 A1, which discloses a folded inverted F antenna (FIFA) which includes an L-shaped receiving element having a first planar portion and a second planar portion connected along a fold edge. A printed circuit board (PCB) is disposed perpendicular to the second planar portion forming a PCB ground plane. The FIFA includes a second ground plane disposed below and in parallel with the second planar portion. Shorting conductors couple the receiving element to the PCB and the second ground plane, and a receive conductor couples a receiver circuit to the receiving element. The FIFA is for use in a wireless communications device, such as a cellular phone, for receiving position signals from a GPS satellite.
Despite the availability of such GPS antenna configurations, other GPS antenna configurations may be desirable which are relatively compact yet still provide desired beam direction or shaping for optimizing GPS satellite signal reception, for example.